I can only look at Unity from an artist's point of view as well as from a business point of view. The Unity editor is miles greater than WED. And MED stinks (I simply cannot stand working in it), but that's okay because there are plenty of 3D modeling applications out there. But from a business perspective, it is hard to beat the one-click publishing to web, PC and MAC and the ability to add on to Unity to export to iOS, Wii, X-Box, etc. With GameStudio you are stuck with PC. And while that may sound nice (something like 95% of computers are PC?), in the business world we have to be concerned about the MAC (some schools use MACs only), iPhone, iPad and all of that. So Unity provides a lot of flexibility for the cost.

I have no choice but to seriously consider Unity for business reasons (as compared to GameStudio).